---
title: "Link’nX KNX trigger: start a scenario on a group address"
description: "Start a Link’nX scenario when a KNX write is received: group address, DPT, expected value, additional addresses and ETS object suggestions."
canonical: https://wiki.can-nx.com/en/guides/link-trigger-knx/
language: en
product: Link’nX
audience:
  - administrateur
  - installateur
context: "Link’nX web: KNX trigger, manual entry or from imported ETS objects"
---

# Link’nX KNX trigger: start a scenario on a group address

Context: Link’nX web: KNX trigger, manual entry or from imported ETS objects

The **KNX** trigger in Link’nX requests a scenario start when a KNX write carries the configured value on one of its group addresses. Only a write counts: a simple status read triggers nothing.

Intended for installers and administrators. To restrict a scenario according to a value or an upper or lower threshold, use the [KNX condition](https://wiki.can-nx.com/en/guides/link-condition-knx/) instead: a condition alone does not create a trigger event.

## Before you start

- You know the group addresses, their DPT and the expected trigger value.
- To get ETS object suggestions, the project’s addresses are [imported into Link’nX](https://wiki.can-nx.com/en/guides/link-knx-file/). Otherwise, enter the parameters manually.

## Create the KNX trigger

1. In **Triggers**, click **Add**, then choose **KNX** in **Select a trigger type**. To edit an existing trigger, open its name or its pencil icon.
2. Fill in **Name**, required, 64 characters maximum.
3. In **Group Address**, enter the main address: three numbers separated by slashes, from 0 to 31, from 0 to 7 and from 0 to 255. **1/1/1** is a fictitious format example.
4. Fill in **DPT**, or search for its number, then select a suggestion. Choose the DPT that matches the data type of the address, not just an accepted format.
5. Fill in **Value** according to this DPT, using the table below. The field must remain filled in when you save.
6. Click the floppy disk icon at the bottom right, then follow the [trigger save confirmations](https://wiki.can-nx.com/en/guides/link-trigger-edit/).

| DPT | **Value** entry |
| --- | --- |
| Starting with **1.** | Choose **True (1)** or **False (0)** |
| Starting with **16.** | Enter the expected text |
| Other numeric types | Enter the exact value to recognize, including 0 if that is the intended value |

## Add additional addresses

Several addresses can cause the same event. They are alternatives: a matching write on any one of them can request the scenario start, without all of them receiving the value at the same time.

1. In the **Additional group address** section, click **Add address**.
2. Fill in the new **Group Address**. Repeat if necessary. All these addresses use the same DPT and the same trigger value.
3. Check each address. **Remove** immediately deletes the additional line from the form; the cross in a field clears it. Remove unnecessary lines and keep a valid main address.

## Fill in the form from ETS objects

If ETS objects are available in this context, you can speed up the entry:

- In **Name**, search for an object’s name and choose the suggestion **name --- address**. The name, the main address and the DPT are then filled in; reread them before continuing.
- In **Group Address**, search for an address or words from the name, then choose **address --- name**. The address and the DPT are copied; check the name of your trigger separately.
- For an additional address, the suggestions take the chosen DPT into account. Check that all additional addresses actually use this DPT.

A search with no results may still concern an existing address: check the context and the DPT already chosen, then shorten the search. If you know the exact parameters, enter them manually.

## Add the trigger to the scenario

[Select the trigger in the scenario](https://wiki.can-nx.com/en/guides/link-compose-scenario/), check the conditions and the actions, then save and check the activation.

Successive writes carrying the same value can request several starts: this setting is not limited to a change of value.

## Check the result

Reopen the trigger to check the saved name, all the addresses, the DPT and the value. When the scenario’s actions can run safely, send the expected value to one of the addresses, for example with a push button or the ETS group monitor, then check the start in [the history](https://wiki.can-nx.com/en/guides/link-history/).

## Troubleshooting

| Message or symptom | Action |
| --- | --- |
| Address with an **incorrect pattern** | Check the three numbers and the slashes |
| Missing or malformed DPT | Re-enter its exact number, for example in the format **1.001**, without concluding that it suits your equipment |
| Value flagged **required** | Choose the option or enter the expected number or text |
| The scenario does not start | Check the saved parameters, the trigger selection in the scenario, its conditions and its activation, then the history |

Do not repeat test writes: they can command equipment. If you do not know the parameters, if the expected ETS suggestions are missing or if the result remains unexplained, contact support@can-nx.com with the context, the object or address concerned, the DPT, the expected value, the time and the checks already made.